Rep. Jerry McNerney, D-Calif., wrapped up the week with some laughs in the service of science.

Taking the stage at a science comedy night show at DC Improv on Thursday night, the congressman talked about his background and what it’s like to be a scientist in Congress. McNerney is a former wind-turbine engineer and holds a doctorate in mathematics.

An organization dedicated to electing scientists and STEM professionals is endorsing four more Democratic House challengers Monday.

Monday’s congressional endorsements — part of a broader rollout of state and local candidates – comes in traditionally GOP seats, two of which may look more competitive for Democrats in 2018, while two others still look more challenging to flip.

Virginia Rep. Gerald E. Connolly is one of the latest Democratic House members to say that he won’t attend Donald Trump’s inauguration. (Tom Williams/CQ Roll Call file photo)

Even before President-elect Donald Trump attacked Georgia Rep. John Lewis on Twitter over the weekend, a handful of Democratic lawmakers had planned to boycott Trump's inauguration on Friday.

But by the end of the Martin Luther King Jr. Day holiday on Monday night, that group had ballooned. As of Friday morning, nearly 70 Democrats in the House said they will not attend out of protest. Several other House Democrats are not attending for medical or other reasons. No Democratic senators have announced intentions to boycott.

No one paid much attention to Doug Applegate’s challenge to California Rep. Darrell Issa until there were only five months left in the campaign, and the Democrat came within 2 points of knocking off the Republican incumbent.